Recent trends in polysaccharide-based and polymer blend nanomaterials for ocular drug delivery: A conceptual perspective

Natural polymers have gained considerable attention in recent years due to their intrinsic biocompatibility, biodegradability, and environmental friendliness, making them highly attractive for biomedical and pharmaceutical applications. These biopolymers—such as chitosan, alginate, gelatin, collagen, cellulose, hyaluronic acid, and silk fibroin—are derived from renewable biological sources and exhibit unique physicochemical properties suitable for fabricating drug delivery systems. The versatility of natural polymers allows them to be formulated into various delivery platforms including nanoparticles, hydrogels, films, microspheres, and scaffolds, which can be tailored to achieve controlled release, site-specific targeting, and enhanced bioavailability of therapeutic agents. Additionally, these polymers often possess inherent biological activities such as antimicrobial properties, hemostatic effects, and cell-adhesion capabilities, which further augment their potential in therapeutic settings. This review provides a comprehensive overview of the classification, characteristics, and processing techniques of key natural polymers and explores their integration into drug delivery systems. Particular emphasis is placed on their role in wound healing, tissue engineering, and targeted therapy. Despite their many advantages, natural polymers are not without challenges, including variability in source quality, limited mechanical strength, and potential immunogenicity. However, advancements in polymer modification, blending with synthetic counterparts, and incorporation of nanotechnology are rapidly addressing these limitations. Overall, the application of natural polymers in drug delivery represents a sustainable and innovative approach in modern medicine, offering safe, effective, and customizable solutions for a wide range of therapeutic needs.